// The MIT License (MIT)

// Copyright (c) 2008 Jacob Seidelin

// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
namespace egret.experimental {
    /**
     * @private
     */
    export let debug = false;
    export const ExifTags = {
        0x9000: "ExifVersion",             
        0xA000: "FlashpixVersion",         
        0xA001: "ColorSpace",              
        0xA002: "PixelXDimension",         // Valid width of meaningful image
        0xA003: "PixelYDimension",         // Valid height of meaningful image
        0x9101: "ComponentsConfiguration", // Information about channels
        0x9102: "CompressedBitsPerPixel",  // Compressed bits per pixel

        // user information
        0x927C: "MakerNote",               // Any desired information written by the manufacturer
        0x9286: "UserComment",             // Comments by user

        // related file
        0xA004: "RelatedSoundFile",        // Name of related sound file

        // date and time
        0x9003: "DateTimeOriginal",        // Date and time when the original image was generated
        0x9004: "DateTimeDigitized",       // Date and time when the image was stored digitally
        0x9290: "SubsecTime",              // Fractions of seconds for DateTime
        0x9291: "SubsecTimeOriginal",      // Fractions of seconds for DateTimeOriginal
        0x9292: "SubsecTimeDigitized",     // Fractions of seconds for DateTimeDigitized

        // picture-taking conditions
        0x829A: "ExposureTime",            // Exposure time (in seconds)
        0x829D: "FNumber",                 // F number
        0x8822: "ExposureProgram",         // Exposure program
        0x8824: "SpectralSensitivity",     // Spectral sensitivity
        0x8827: "ISOSpeedRatings",         // ISO speed rating
        0x8828: "OECF",                    // Optoelectric conversion factor
        0x9201: "ShutterSpeedValue",       // Shutter speed
        0x9202: "ApertureValue",           // Lens aperture
        0x9203: "BrightnessValue",         // Value of brightness
        0x9204: "ExposureBias",            // Exposure bias
        0x9205: "MaxApertureValue",        // Smallest F number of lens
        0x9206: "SubjectDistance",         // Distance to subject in meters
        0x9207: "MeteringMode",            // Metering mode
        0x9208: "LightSource",             // Kind of light source
        0x9209: "Flash",                   // Flash status
        0x9214: "SubjectArea",             // Location and area of main subject
        0x920A: "FocalLength",             // Focal length of the lens in mm
        0xA20B: "FlashEnergy",             // Strobe energy in BCPS
        0xA20C: "SpatialFrequencyResponse",    //
        0xA20E: "FocalPlaneXResolution",   // Number of pixels in width direction per FocalPlaneResolutionUnit
        0xA20F: "FocalPlaneYResolution",   // Number of pixels in height direction per FocalPlaneResolutionUnit
        0xA210: "FocalPlaneResolutionUnit",    // Unit for measuring FocalPlaneXResolution and FocalPlaneYResolution
        0xA214: "SubjectLocation",         // Location of subject in image
        0xA215: "ExposureIndex",           // Exposure index selected on camera
        0xA217: "SensingMethod",           // Image sensor type
        0xA300: "FileSource",              // Image source (3 == DSC)
        0xA301: "SceneType",               // Scene type (1 == directly photographed)
        0xA302: "CFAPattern",              // Color filter array geometric pattern
        0xA401: "CustomRendered",          // Special processing
        0xA402: "ExposureMode",            // Exposure mode
        0xA403: "WhiteBalance",            // 1 = auto white balance, 2 = manual
        0xA404: "DigitalZoomRation",       // Digital zoom ratio
        0xA405: "FocalLengthIn35mmFilm",   // Equivalent foacl length assuming 35mm film camera (in mm)
        0xA406: "SceneCaptureType",        // Type of scene
        0xA407: "GainControl",             // Degree of overall image gain adjustment
        0xA408: "Contrast",                // Direction of contrast processing applied by camera
        0xA409: "Saturation",              // Direction of saturation processing applied by camera
        0xA40A: "Sharpness",               // Direction of sharpness processing applied by camera
        0xA40B: "DeviceSettingDescription",    //
        0xA40C: "SubjectDistanceRange",    // Distance to subject

        // other tags
        0xA005: "InteroperabilityIFDPointer",
        0xA420: "ImageUniqueID"            // Identifier assigned uniquely to each image
    }

    export const TiffTags = {
        0x0100: "ImageWidth",
        0x0101: "ImageHeight",
        0x8769: "ExifIFDPointer",
        0x8825: "GPSInfoIFDPointer",
        0xA005: "InteroperabilityIFDPointer",
        0x0102: "BitsPerSample",
        0x0103: "Compression",
        0x0106: "PhotometricInterpretation",
        0x0112: "Orientation",
        0x0115: "SamplesPerPixel",
        0x011C: "PlanarConfiguration",
        0x0212: "YCbCrSubSampling",
        0x0213: "YCbCrPositioning",
        0x011A: "XResolution",
        0x011B: "YResolution",
        0x0128: "ResolutionUnit",
        0x0111: "StripOffsets",
        0x0116: "RowsPerStrip",
        0x0117: "StripByteCounts",
        0x0201: "JPEGInterchangeFormat",
        0x0202: "JPEGInterchangeFormatLength",
        0x012D: "TransferFunction",
        0x013E: "WhitePoint",
        0x013F: "PrimaryChromaticities",
        0x0211: "YCbCrCoefficients",
        0x0214: "ReferenceBlackWhite",
        0x0132: "DateTime",
        0x010E: "ImageDescription",
        0x010F: "Make",
        0x0110: "Model",
        0x0131: "Software",
        0x013B: "Artist",
        0x8298: "Copyright"
    }

    export const GPSTags = {
        0x0000: "GPSVersionID",
        0x0001: "GPSLatitudeRef",
        0x0002: "GPSLatitude",
        0x0003: "GPSLongitudeRef",
        0x0004: "GPSLongitude",
        0x0005: "GPSAltitudeRef",
        0x0006: "GPSAltitude",
        0x0007: "GPSTimeStamp",
        0x0008: "GPSSatellites",
        0x0009: "GPSStatus",
        0x000A: "GPSMeasureMode",
        0x000B: "GPSDOP",
        0x000C: "GPSSpeedRef",
        0x000D: "GPSSpeed",
        0x000E: "GPSTrackRef",
        0x000F: "GPSTrack",
        0x0010: "GPSImgDirectionRef",
        0x0011: "GPSImgDirection",
        0x0012: "GPSMapDatum",
        0x0013: "GPSDestLatitudeRef",
        0x0014: "GPSDestLatitude",
        0x0015: "GPSDestLongitudeRef",
        0x0016: "GPSDestLongitude",
        0x0017: "GPSDestBearingRef",
        0x0018: "GPSDestBearing",
        0x0019: "GPSDestDistanceRef",
        0x001A: "GPSDestDistance",
        0x001B: "GPSProcessingMethod",
        0x001C: "GPSAreaInformation",
        0x001D: "GPSDateStamp",
        0x001E: "GPSDifferential"
    }

    export const StringValues = {
        ExposureProgram: {
            0: "Not defined",
            1: "Manual",
            2: "Normal program",
            3: "Aperture priority",
            4: "Shutter priority",
            5: "Creative program",
            6: "Action program",
            7: "Portrait mode",
            8: "Landscape mode"
        },
        MeteringMode: {
            0: "Unknown",
            1: "Average",
            2: "CenterWeightedAverage",
            3: "Spot",
            4: "MultiSpot",
            5: "Pattern",
            6: "Partial",
            255: "Other"
        },
        LightSource: {
            0: "Unknown",
            1: "Daylight",
            2: "Fluorescent",
            3: "Tungsten (incandescent light)",
            4: "Flash",
            9: "Fine weather",
            10: "Cloudy weather",
            11: "Shade",
            12: "Daylight fluorescent (D 5700 - 7100K)",
            13: "Day white fluorescent (N 4600 - 5400K)",
            14: "Cool white fluorescent (W 3900 - 4500K)",
            15: "White fluorescent (WW 3200 - 3700K)",
            17: "Standard light A",
            18: "Standard light B",
            19: "Standard light C",
            20: "D55",
            21: "D65",
            22: "D75",
            23: "D50",
            24: "ISO studio tungsten",
            255: "Other"
        },
        Flash: {
            0x0000: "Flash did not fire",
            0x0001: "Flash fired",
            0x0005: "Strobe return light not detected",
            0x0007: "Strobe return light detected",
            0x0009: "Flash fired, compulsory flash mode",
            0x000D: "Flash fired, compulsory flash mode, return light not detected",
            0x000F: "Flash fired, compulsory flash mode, return light detected",
            0x0010: "Flash did not fire, compulsory flash mode",
            0x0018: "Flash did not fire, auto mode",
            0x0019: "Flash fired, auto mode",
            0x001D: "Flash fired, auto mode, return light not detected",
            0x001F: "Flash fired, auto mode, return light detected",
            0x0020: "No flash function",
            0x0041: "Flash fired, red-eye reduction mode",
            0x0045: "Flash fired, red-eye reduction mode, return light not detected",
            0x0047: "Flash fired, red-eye reduction mode, return light detected",
            0x0049: "Flash fired, compulsory flash mode, red-eye reduction mode",
            0x004D: "Flash fired, compulsory flash mode, red-eye reduction mode, return light not detected",
            0x004F: "Flash fired, compulsory flash mode, red-eye reduction mode, return light detected",
            0x0059: "Flash fired, auto mode, red-eye reduction mode",
            0x005D: "Flash fired, auto mode, return light not detected, red-eye reduction mode",
            0x005F: "Flash fired, auto mode, return light detected, red-eye reduction mode"
        },
        SensingMethod: {
            1: "Not defined",
            2: "One-chip color area sensor",
            3: "Two-chip color area sensor",
            4: "Three-chip color area sensor",
            5: "Color sequential area sensor",
            7: "Trilinear sensor",
            8: "Color sequential linear sensor"
        },
        SceneCaptureType: {
            0: "Standard",
            1: "Landscape",
            2: "Portrait",
            3: "Night scene"
        },
        SceneType: {
            1: "Directly photographed"
        },
        CustomRendered: {
            0: "Normal process",
            1: "Custom process"
        },
        WhiteBalance: {
            0: "Auto white balance",
            1: "Manual white balance"
        },
        GainControl: {
            0: "None",
            1: "Low gain up",
            2: "High gain up",
            3: "Low gain down",
            4: "High gain down"
        },
        Contrast: {
            0: "Normal",
            1: "Soft",
            2: "Hard"
        },
        Saturation: {
            0: "Normal",
            1: "Low saturation",
            2: "High saturation"
        },
        Sharpness: {
            0: "Normal",
            1: "Soft",
            2: "Hard"
        },
        SubjectDistanceRange: {
            0: "Unknown",
            1: "Macro",
            2: "Close view",
            3: "Distant view"
        },
        FileSource: {
            3: "DSC"
        },

        Components: {
            0: "",
            1: "Y",
            2: "Cb",
            3: "Cr",
            4: "R",
            5: "G",
            6: "B"
        }
    }

    function addEvent(element, event, handler) {
        if (element.addEventListener) {
            element.addEventListener(event, handler, false);
        } else if (element.attachEvent) {
            element.attachEvent("on" + event, handler);
        }
    }

    function imageHasData(img) {
        return !!(img.exifdata);
    }


    function base64ToArrayBuffer(base64, contentType) {
        contentType = contentType || base64.match(/^data\:([^\;]+)\;base64,/mi)[1] || ''; // e.g. 'data:image/jpeg;base64,...' => 'image/jpeg'
        base64 = base64.replace(/^data\:([^\;]+)\;base64,/gmi, '');
        var binary = atob(base64);
        var len = binary.length;
        var buffer = new ArrayBuffer(len);
        var view = new Uint8Array(buffer);
        for (var i = 0; i < len; i++) {
            view[i] = binary.charCodeAt(i);
        }
        return buffer;
    }

    function objectURLToBlob(url, callback) {
        var http = new XMLHttpRequest();
        http.open("GET", url, true);
        http.responseType = "blob";
        http.onload = function (e) {
            if (this["status"] == 200 || this["status"] === 0) {
                callback(this["response"]);
            }
        };
        http.send();
    }

    function getImageData(img, callback) {
        function handleBinaryFile(binFile) {
            var data = findEXIFinJPEG(binFile);
            var iptcdata = findIPTCinJPEG(binFile);
            img.exifdata = data || {};
            img.iptcdata = iptcdata || {};
            if (callback) {
                callback.call(img);
            }
        }

        if (img.src) {
            if (/^data\:/i.test(img.src)) { // Data URI
                var arrayBuffer = base64ToArrayBuffer(img.src,"");
                handleBinaryFile(arrayBuffer);

            } else if (/^blob\:/i.test(img.src)) { // Object URL
                var fileReader = new FileReader();
                fileReader.onload = function (e) {
                    handleBinaryFile(e.target["result"]);
                };
                objectURLToBlob(img.src, function (blob) {
                    fileReader.readAsArrayBuffer(blob);
                });
            } else {
                var http = new XMLHttpRequest();
                http.onload = function () {
                    if (this["status"] == 200 || this["status"] === 0) {
                        handleBinaryFile(http.response);
                    } else {
                        throw "Could not load image";
                    }
                    http = null;
                };
                http.open("GET", img.src, true);
                http.responseType = "arraybuffer";
                http.send(null);
            }
        } else if (window["FileReader"] && (img instanceof window.Blob || img instanceof window["File"])) {
            var fileReader = new FileReader();
            fileReader.onload = function (e) {
                if (debug) console.log("Got file of length " + e.target["result"].byteLength);
                handleBinaryFile(e.target["result"]);
            };

            fileReader.readAsArrayBuffer(img);
        }
    }

    function findEXIFinJPEG(file) {
        var dataView = new DataView(file);

        if (debug) console.log("Got file of length " + file.byteLength);
        if ((dataView.getUint8(0) != 0xFF) || (dataView.getUint8(1) != 0xD8)) {
            if (debug) console.log("Not a valid JPEG");
            return false; // not a valid jpeg
        }

        var offset = 2,
            length = file.byteLength,
            marker;

        while (offset < length) {
            if (dataView.getUint8(offset) != 0xFF) {
                if (debug) console.log("Not a valid marker at offset " + offset + ", found: " + dataView.getUint8(offset));
                return false; // not a valid marker, something is wrong
            }

            marker = dataView.getUint8(offset + 1);
            if (debug) console.log(marker);

            // we could implement handling for other markers here,
            // but we're only looking for 0xFFE1 for EXIF data

            if (marker == 225) {
                if (debug) console.log("Found 0xFFE1 marker");

                return readEXIFData(dataView, offset + 4);

                // offset += 2 + file.getShortAt(offset+2, true);

            } else {
                offset += 2 + dataView.getUint16(offset + 2);
            }

        }

    }

    function findIPTCinJPEG(file) {
        var dataView = new DataView(file);

        if (debug) console.log("Got file of length " + file.byteLength);
        if ((dataView.getUint8(0) != 0xFF) || (dataView.getUint8(1) != 0xD8)) {
            if (debug) console.log("Not a valid JPEG");
            return false; // not a valid jpeg
        }

        var offset = 2,
            length = file.byteLength;


        var isFieldSegmentStart = function (dataView, offset) {
            return (
                dataView.getUint8(offset) === 0x38 &&
                dataView.getUint8(offset + 1) === 0x42 &&
                dataView.getUint8(offset + 2) === 0x49 &&
                dataView.getUint8(offset + 3) === 0x4D &&
                dataView.getUint8(offset + 4) === 0x04 &&
                dataView.getUint8(offset + 5) === 0x04
            );
        };

        while (offset < length) {

            if (isFieldSegmentStart(dataView, offset)) {

                // Get the length of the name header (which is padded to an even number of bytes)
                var nameHeaderLength = dataView.getUint8(offset + 7);
                if (nameHeaderLength % 2 !== 0) nameHeaderLength += 1;
                // Check for pre photoshop 6 format
                if (nameHeaderLength === 0) {
                    // Always 4
                    nameHeaderLength = 4;
                }

                var startOffset = offset + 8 + nameHeaderLength;
                var sectionLength = dataView.getUint16(offset + 6 + nameHeaderLength);

                return readIPTCData(file, startOffset, sectionLength);

                break;

            }


            // Not the marker, continue searching
            offset++;

        }

    }
    const IptcFieldMap = {
        0x78: 'caption',
        0x6E: 'credit',
        0x19: 'keywords',
        0x37: 'dateCreated',
        0x50: 'byline',
        0x55: 'bylineTitle',
        0x7A: 'captionWriter',
        0x69: 'headline',
        0x74: 'copyright',
        0x0F: 'category'
    };

    function readIPTCData(file, startOffset, sectionLength) {
        var dataView = new DataView(file);
        var data = {};
        var fieldValue, fieldName, dataSize, segmentType, segmentSize;
        var segmentStartPos = startOffset;
        while (segmentStartPos < startOffset + sectionLength) {
            if (dataView.getUint8(segmentStartPos) === 0x1C && dataView.getUint8(segmentStartPos + 1) === 0x02) {
                segmentType = dataView.getUint8(segmentStartPos + 2);
                if (segmentType in IptcFieldMap) {
                    dataSize = dataView.getInt16(segmentStartPos + 3);
                    segmentSize = dataSize + 5;
                    fieldName = IptcFieldMap[segmentType];
                    fieldValue = getStringFromDB(dataView, segmentStartPos + 5, dataSize);
                    // Check if we already stored a value with this name
                    if (data.hasOwnProperty(fieldName)) {
                        // Value already stored with this name, create multivalue field
                        if (data[fieldName] instanceof Array) {
                            data[fieldName].push(fieldValue);
                        }
                        else {
                            data[fieldName] = [data[fieldName], fieldValue];
                        }
                    }
                    else {
                        data[fieldName] = fieldValue;
                    }
                }

            }
            segmentStartPos++;
        }
        return data;
    }

    function readTags(file, tiffStart, dirStart, strings, bigEnd) {
        var entries = file.getUint16(dirStart, !bigEnd),
            tags = {},
            entryOffset, tag,
            i;

        for (i = 0; i < entries; i++) {
            entryOffset = dirStart + i * 12 + 2;
            tag = strings[file.getUint16(entryOffset, !bigEnd)];
            if (!tag && debug) console.log("Unknown tag: " + file.getUint16(entryOffset, !bigEnd));
            tags[tag] = readTagValue(file, entryOffset, tiffStart, dirStart, bigEnd);
        }
        return tags;
    }


    function readTagValue(file, entryOffset, tiffStart, dirStart, bigEnd) {
        var type = file.getUint16(entryOffset + 2, !bigEnd),
            numValues = file.getUint32(entryOffset + 4, !bigEnd),
            valueOffset = file.getUint32(entryOffset + 8, !bigEnd) + tiffStart,
            offset,
            vals, val, n,
            numerator, denominator;

        switch (type) {
            case 1: // byte, 8-bit unsigned int
            case 7: // undefined, 8-bit byte, value depending on field
                if (numValues == 1) {
                    return file.getUint8(entryOffset + 8, !bigEnd);
                } else {
                    offset = numValues > 4 ? valueOffset : (entryOffset + 8);
                    vals = [];
                    for (n = 0; n < numValues; n++) {
                        vals[n] = file.getUint8(offset + n);
                    }
                    return vals;
                }

            case 2: // ascii, 8-bit byte
                offset = numValues > 4 ? valueOffset : (entryOffset + 8);
                return getStringFromDB(file, offset, numValues - 1);

            case 3: // short, 16 bit int
                if (numValues == 1) {
                    return file.getUint16(entryOffset + 8, !bigEnd);
                } else {
                    offset = numValues > 2 ? valueOffset : (entryOffset + 8);
                    vals = [];
                    for (n = 0; n < numValues; n++) {
                        vals[n] = file.getUint16(offset + 2 * n, !bigEnd);
                    }
                    return vals;
                }

            case 4: // long, 32 bit int
                if (numValues == 1) {
                    return file.getUint32(entryOffset + 8, !bigEnd);
                } else {
                    vals = [];
                    for (n = 0; n < numValues; n++) {
                        vals[n] = file.getUint32(valueOffset + 4 * n, !bigEnd);
                    }
                    return vals;
                }

            case 5:    // rational = two long values, first is numerator, second is denominator
                if (numValues == 1) {
                    numerator = file.getUint32(valueOffset, !bigEnd);
                    denominator = file.getUint32(valueOffset + 4, !bigEnd);
                    val = new Number(numerator / denominator);
                    val.numerator = numerator;
                    val.denominator = denominator;
                    return val;
                } else {
                    vals = [];
                    for (n = 0; n < numValues; n++) {
                        numerator = file.getUint32(valueOffset + 8 * n, !bigEnd);
                        denominator = file.getUint32(valueOffset + 4 + 8 * n, !bigEnd);
                        vals[n] = new Number(numerator / denominator);
                        vals[n].numerator = numerator;
                        vals[n].denominator = denominator;
                    }
                    return vals;
                }

            case 9: // slong, 32 bit signed int
                if (numValues == 1) {
                    return file.getInt32(entryOffset + 8, !bigEnd);
                } else {
                    vals = [];
                    for (n = 0; n < numValues; n++) {
                        vals[n] = file.getInt32(valueOffset + 4 * n, !bigEnd);
                    }
                    return vals;
                }

            case 10: // signed rational, two slongs, first is numerator, second is denominator
                if (numValues == 1) {
                    return file.getInt32(valueOffset, !bigEnd) / file.getInt32(valueOffset + 4, !bigEnd);
                } else {
                    vals = [];
                    for (n = 0; n < numValues; n++) {
                        vals[n] = file.getInt32(valueOffset + 8 * n, !bigEnd) / file.getInt32(valueOffset + 4 + 8 * n, !bigEnd);
                    }
                    return vals;
                }
        }
    }

    function getStringFromDB(buffer, start, length) {
        var outstr = "";
        for (var n = start; n < start + length; n++) {
            outstr += String.fromCharCode(buffer.getUint8(n));
        }
        return outstr;
    }

    function readEXIFData(file, start) {
        if (getStringFromDB(file, start, 4) != "Exif") {
            if (debug) console.log("Not valid EXIF data! " + getStringFromDB(file, start, 4));
            return false;
        }

        var bigEnd,
            tags, tag,
            exifData, gpsData,
            tiffOffset = start + 6;

        // test for TIFF validity and endianness
        if (file.getUint16(tiffOffset) == 0x4949) {
            bigEnd = false;
        } else if (file.getUint16(tiffOffset) == 0x4D4D) {
            bigEnd = true;
        } else {
            if (debug) console.log("Not valid TIFF data! (no 0x4949 or 0x4D4D)");
            return false;
        }

        if (file.getUint16(tiffOffset + 2, !bigEnd) != 0x002A) {
            if (debug) console.log("Not valid TIFF data! (no 0x002A)");
            return false;
        }

        var firstIFDOffset = file.getUint32(tiffOffset + 4, !bigEnd);

        if (firstIFDOffset < 0x00000008) {
            if (debug) console.log("Not valid TIFF data! (First offset less than 8)", file.getUint32(tiffOffset + 4, !bigEnd));
            return false;
        }

        tags = readTags(file, tiffOffset, tiffOffset + firstIFDOffset, TiffTags, bigEnd);

        if (tags.ExifIFDPointer) {
            exifData = readTags(file, tiffOffset, tiffOffset + tags.ExifIFDPointer, ExifTags, bigEnd);
            for (tag in exifData) {
                switch (tag) {
                    case "LightSource":
                    case "Flash":
                    case "MeteringMode":
                    case "ExposureProgram":
                    case "SensingMethod":
                    case "SceneCaptureType":
                    case "SceneType":
                    case "CustomRendered":
                    case "WhiteBalance":
                    case "GainControl":
                    case "Contrast":
                    case "Saturation":
                    case "Sharpness":
                    case "SubjectDistanceRange":
                    case "FileSource":
                        exifData[tag] = StringValues[tag][exifData[tag]];
                        break;

                    case "ExifVersion":
                    case "FlashpixVersion":
                        exifData[tag] = String.fromCharCode(exifData[tag][0], exifData[tag][1], exifData[tag][2], exifData[tag][3]);
                        break;

                    case "ComponentsConfiguration":
                        exifData[tag] =
                            StringValues.Components[exifData[tag][0]] +
                            StringValues.Components[exifData[tag][1]] +
                            StringValues.Components[exifData[tag][2]] +
                            StringValues.Components[exifData[tag][3]];
                        break;
                }
                tags[tag] = exifData[tag];
            }
        }

        if (tags.GPSInfoIFDPointer) {
            gpsData = readTags(file, tiffOffset, tiffOffset + tags.GPSInfoIFDPointer, GPSTags, bigEnd);
            for (tag in gpsData) {
                switch (tag) {
                    case "GPSVersionID":
                        gpsData[tag] = gpsData[tag][0] +
                            "." + gpsData[tag][1] +
                            "." + gpsData[tag][2] +
                            "." + gpsData[tag][3];
                        break;
                }
                tags[tag] = gpsData[tag];
            }
        }

        return tags;
    }

    export class EXIF {
        static getData(img, callback) {
            if ((img instanceof Image || img instanceof HTMLImageElement) && !img.complete) return false;

            if (!imageHasData(img)) {
                getImageData(img, callback);
            } else {
                if (callback) {
                    callback.call(img);
                }
            }
            return true;
        }
        static getTag(img, tag) {
            if (!imageHasData(img)) return;
            return img.exifdata[tag];
        }
        static getIptcTag(img, tag) {
            if (!imageHasData(img)) return;
            return img.iptcdata[tag];
        }
        static getAllTags(img) {
            if (!imageHasData(img)) return {};
            var a,
                data = img.exifdata,
                tags = {};
            for (a in data) {
                if (data.hasOwnProperty(a)) {
                    tags[a] = data[a];
                }
            }
            return tags;
        }
        static getAllIptcTags(img) {
            if (!imageHasData(img)) return {};
            var a,
                data = img.iptcdata,
                tags = {};
            for (a in data) {
                if (data.hasOwnProperty(a)) {
                    tags[a] = data[a];
                }
            }
            return tags;
        }
        static pretty(img) {
            if (!imageHasData(img)) return "";
            var a,
                data = img.exifdata,
                strPretty = "";
            for (a in data) {
                if (data.hasOwnProperty(a)) {
                    if (typeof data[a] == "object") {
                        if (data[a] instanceof Number) {
                            strPretty += a + " : " + data[a] + " [" + data[a].numerator + "/" + data[a].denominator + "]\r\n";
                        } else {
                            strPretty += a + " : [" + data[a].length + " values]\r\n";
                        }
                    } else {
                        strPretty += a + " : " + data[a] + "\r\n";
                    }
                }
            }
            return strPretty;
        }
        static readFromBinaryFile(file) {
            return findEXIFinJPEG(file);
        }
    }
}